The characterization and marketing of naturally occurring antioxidants is receiving widespread attention in the everyday lives of many people today. Certain food groups having high levels of antioxidants are believed to provide prophylactic health benefits. Therefore, a myriad of supplements, herbal formulations, and herbal extracts are being marketed to consumers. In many cases, these “elixirs” are sold without solid scientific foundation. Currently, there is increased scientific interest in the role of antioxidants and the part they play in human health by reducing excessive free radicals.
Free radicals are oxygen atoms that contain unpaired hydrogen electrons. Free radicals are very unstable and react quickly with other compounds, trying to capture the needed electron to gain stability. Generally, free radicals attack the nearest stable molecule and grab its electron. When the attacked molecule loses an electron, it becomes a free radical itself, beginning a chain reaction. Once the process is started it can cascade, finally resulting in the disruption of a living cell.
Some free radicals arise normally during metabolism. For example, the immune system cells of the body purposely create free radicals to neutralize viruses and bacteria. However, environmental factors such as pollution, radiation, cigarette smoke and herbicides can result in the production of an excessive amount of free radical formation.
Normally, the body can accommodate free radicals. However, if antioxidants are unavailable or the free radical production becomes excessive, damage can occur. It is well known that free radical damage accumulates with age.
Many free radical supplements, based on natural food stuffs, herbal ingredients, herbal extracts and formulations thereof, are available on the market. These supplements allegedly contain components that somehow either prevent the formation of or quickly react with the chemically reactive free radical species such as singlet oxygen, peroxides, and the hydroxy free radicals.
Three highly touted antioxidants, vitamin C, vitamin E, and beta-carotene, and their role as antioxidants have received high scientific scrutiny. These antioxidants are abundant in foodstuffs associated with good health and are readily available over the counter as dietary supplements. Chemically they are known to react with molecular oxygen and with other selected free radicals. These antioxidants provides a source of electrons to the reactive radical thus terminating the propagation step and intercepting the free radical before it can react with other biological molecules. The exact mechanism of how these compounds operate as scavengers of free radicals in the body is not known. Other classes of antioxidants include the flavenoids, isoflavenoids, and other natural occurring compounds that contain reactive phenolic groups.
Scientists have devised some tests to measure the effectiveness with which antioxidants react with free radicals. These assays are generally based on the reaction of free radicals such as peroxides, singlet oxygen, or hydroxy radicals with free radical inhibitors. However, the isolation of additional antioxidants and the ability to rapidly and reliably testing foods or nutritional substances for the presence of antioxidants is lacking.
Therefore, there is a need for the identification and isolation of additional antioxidants so that nutritional supplements containing the antioxidants can be made available to health conscious consumers or individuals particularly susceptible to the accumulation of excessive free radicals. There is also a need for antioxidants for use in removing oxidants from various substances, such as tobacco products. Reliable methods for determining whether a particular food or nutritional substance contains the desired antioxidants are also needed.